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Title: Review of the microtox toxicity test
Author: W. Young
Author: R. Butler
Author: I. Johnson
Document Type: Monograph
This review compares the sensitivity of Microtox with other organisms used in toxicity tests (including fathead minnow, rainbow trout, oyster embryos, Daphnia and Chlorella pyrenoidosa) . It also describes the potential applications, advantages and limitations of the test. Microtox was found to have a sensitivity comparable with other test organisms, for many pure and complex test substances. Microtox sensitivity and the correlation with other tests increased and data variability decreased for many industrial effluents, as their complexity and toxicity increased. However, Microtox was relatively insensitive to certain simple Organics such as ammonia, chloroform, cyanide and effluents or leachates containing a high proportion of insecticides, herbicides, inorganics, or highly lipophillic contaminants. Although Microtox is often less sensitive than higher organism toxicity tests, Microtox EC50 values and acute LC50 values for higher test species do not normally differ by more than one order of magnitude. Therefore a "tiered approach" is recommended whereby Microtox is used to rank effluent toxicity and identify priority effluents. Additional more costly tests can then be limited to priority effluents and those to which Microtox is known to be relatively insensitive. For complex effluents Microtox can be calibrated against more sensitive tests, and then used routinely to monitor the compliance of effluents with derived toxicity-based consent conditions.
Publisher: National Rivers Authority
Publication Date: 1991
Publication Place: Bristol
Subject Keywords: ToxicityTestingEvaluation
Extent: 81
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